The invention relates to a sensor device, particularly a limit or threshold value sensor device with a sensor system for detecting an external measured quantity, a switching device being provided for switching a load circuit.The known design of the switching device by means of transistors or electromechanical relays has always necessitated compromises with regards to the electronic functionality, design of the circuit and arrangement on or with the sensor device.The solution provided by the invention is a switching device with an almost wattless drive and galvanic separation or isolation between the control circuit and output circuit, the sensor system being constructed independent of the load circuit.